/**
 * Created with IntelliJ IDEA.
 * Description:
 * User:${USER}
 * Date:${YEAR}-${MONTH}-${DAY}
 * ${TIME}
 */
public class Main {
    public static void main(String[] args) {
        System.out.println("Hello world!");
    }
    public String longestPalindrome(String s) {
        int n=s.length();int begin=0;
        int len=0;
        for(int i=0;i<n;i++){
            int left=i,right=i;
            while(left>=0&&right<n&&s.charAt(left)==s.charAt(right)){
                left--;right++;
            }
            if(right-left-1>len){
                begin=left+1;
                len=right-left-1;
            }
            left=i;
            right=i+1;
            while(left>=0&&right<n&&s.charAt(left)==s.charAt(right)){
                left--;right++;
            }
            if(right-left-1>len){
                begin=left+1;
                len=right-left-1;
            }
        }
        return s.substring(begin,begin+len);
    }
}